1. Field of Invention
The present invention relates to a method of manufacturing an electronic part, the electronic part manufactured according to the method, a method of mounting the electronic part, and an electronic apparatus.
2. Description of Related Art
Electronic parts, such as an IC, etc. are mounted onto a circuit board etc. for use. Various methods are proposed to mount the electronic part onto the circuit board. FIG. 9 shows a view for explaining a method of mounting the electronic part according to the related art. As shown in FIG. 9(A), the electronic part 170, such as the IC, etc. is mounted onto the counterpart substrate 120 while interposing an anisotropic conductive film (ACF) 190 therebetween. Conductive particles 195 distributed in a thermosetting resin 192 form the anisotropic conductive film 190. The conductive particles 195 are interposed between the electrode pad 172 formed on the active surface of the electronic part 170 and the electrode pad 122 formed on the surface of the counterpart substrate 120, thereby the electrode pads are electrically connected. Also, due to the thermosetting resin 192 thermally set by heating, the counterpart substrate 120 is mechanically connected to the electronic part 170.
Recently, as electronic parts have become smaller, the electrode pads must be arranged with a finer pitch. Since the conductive particles 195 are arranged between the electrode pads which are neighboring horizontally, the mounting method using the anisotropic conductive film can cause a short circuit between adjacent the electrode pads. Also, as the pitch of the pattern of the electrode pads becomes finer, the electrode pad itself becomes smaller, so the number of conductive particles contacted by the electrode pads is decreased and the reliability of the electrical connection is reduced. Also, the expensive conductive particles cannot be used for all of the electrical connection.
Herein, Japanese Unexamined Patent Application Publication No. 7-6799, Japanese Unexamined Patent Application Publication No. 10-84178 and Japanese Unexamined Patent Application Publication No. 2002-170837 disclose structures that do not arrange the conductive particles between the neighboring electrode pads because the conductive particles are previously bonded to the surface of the electrode pad of the electronic part before the part is mounted to the counterpart substrate.
FIG. 9(B) shows a view for explaining a mounting method disclosed in Japanese Unexamined Patent Application Publication No. 2002-170837. In this mounting method, adhesive conductive particles 298 are formed by coating the conductive particles 295 with an adhesive 296, and the adhesive conductive particles 298 are fixed onto the surface of the electrode pad 272 of the electronic part 270. The fixing method is as follows: First, a resist film 280 is formed on a portion of the active surface of the electronic part 270 excluding the formation portion of the electrode pad 272. Next, the adhesive conductive particles 298 are distributed on the surface of the electronic part 270 and heated and pressed to bond the distributed adhesive conductive particles 298 thereon. Thereby, the adhesive conductive particles 298 are fixed on the entire active surface of the electronic part 270. Next, the resist film 280 is removed together with the adhesive conductive particles 298 fixed on the surface of the resist film 280, leaving the adhesive conductive particles which are fixed to the electrode pad 272. Therefore, the adhesive conductive particles 298 are fixed only on the surface of the electrode pad 272. The position of the remaining adhesive conductive particles 298 to be connected with the electrode pad 222 of the counterpart substrate 220 is determined, and then the electronic part 270 is pressed to the counterpart substrate 220 with heat. Thus, as the adhesives 296 of the adhesive conductive particles 298 are dissolved, the electronic part 270 mechanically connects to the counterpart substrate 220 and at the same time they are electrically connected by the disposed conductive particles 295.